Note: This post first appeared at the Post Partisan blog at WashingtonPost.com. 

This week in Los Angeles, anti-medicinal marijuana zealots may have inadvertently put themselves, and their cause, into the middle of Zeno’s Dichotomy Paradox. Simply put, the paradox posits that in order for one to reach his goal, he must first get half-way there (1/2). But to reach half-way, he must get half-way to half-way (1/4). And then half-way to half-way to half-way (1/8). And so on, thereby reaching an infinite number of midpoints on his path while never actually arriving at the end. The L.A. City Council’s new ordinance to close 439 medicinal marijuana dispensaries, which goes into effect on June 7, is but a mid-point in the paradox describing the gap between the city’s current pot policy and outright, old-style prohibition.

Perhaps sensing that in 2010, abolishing medicinal marijuana is no longer a viable legislative option (Medicinal Marijuana was approved by California voters in the Compassionate Use Act of 1996), the L.A. City Council has gone half-way, electing to close only medicinal marijuana dispensaries that opened after a 2007 moratorium declared that the city wouldn’t sanction any more than it already had. This is a far cry from “Summer of Love,” but it isn’t exactly “Just Say No,” either. Even with the June closings, Angelenos will still be served by more than 130 businesses that opened and registered with the city, county, and state before the moratorium. Using Zeno as a model, we might expect this half-measure to be followed by another, and possibly another—but implicit in those half-measures is a capitulation that arriving back at the good old days of Reefer Madness is a hopeless cause.

Its a sign of the times, then – and no coincidence – that this week the D.C. City Council gave final approval to regulated, legalized medicinal marijuana within the District. It is telling that, at the same time Los Angeles seems to have given up on eradicating the killer weed from its environs, Washington D.C. is beginning its own birth pangs of liberalization and legalization. Thought it would appear that L.A. is cracking down while D.C. is easing up, they’re actually related parts of a larger, progressive trend towards comprehensive drug law reform.